Article

Features of hospital and emergency medical service in out-of-hospital cardiac arrest patients with shockable rhythm

a b s t r a c t

Objective: Predicting the outcome of out-of-hospital cardiac arrest (OHCA) patients is crucial. We examined hos- pital characteristics and parameters of emergency medical service (including scene time interval and direct am- bulance delivery to intensive heart hospitals) as survival or outcome predictors.

Study design: Data from 546 consecutive OHCA shockable patients treated between January 2012 and December 2015 in Taoyuan City (Taiwan, ROC) were collected. In addition to demographic data, location of arrest, initial rhythm, availability of a hospital with or without 24/7 percutaneous coronary intervention (PCI), emergency medical service (EMS) time, provision of cardiopulmonary resuscitation by a bystander, presence of a witness at collapse, and level of life support were analysed.

Results: Multivariate analysis showed that hospitalisation with immediate PCI availability was an independent predictor (OR: 4.32; 95% CI: 1.27-14.70) solely for the outcome of survival until discharge. The presence of a wit- ness while collapsing (OR: 3.52; 95% CI: 1.03-11.98), EMS response time (OR: 0.83; 95% CI: 0.70-0.98), and scene time interval (STI; OR: 0.89; 95% CI: 0.81-0.99) were valuable for predicting the neurological outcome.

Conclusions: Direct ambulance delivery to intensive heart hospitals that had 24/7 PCI availability was associated with a higher probability of surviving until discharge in OHCA patients with Shockable rhythms. Similarly, a witnessed collapse was correlated with being discharged alive from hospital and recovering with good cerebral performance. In addition, longer response time and scene time interval indicated poorer survival and neurolog- ical outcome.

(C) 2017

Introduction

Being a leading cause of death, the high mortality and morbidity of out-of-hospital cardiac arrest (OHCA) render it a challenge for healthcare systems. According to a 2016 report, around 356,500 persons experience emergency medical service (EMS)-assessed OHCA annually in the United States alone, which has a low overall survival rate of 12%

[1] despite efforts to improve resuscitative and post-resuscitative care. Among patients treated by EMS, up to 22.9% have an initial rhythm of ventricular fibrillation (VF), Ventricular tachycardia , or a shockable

* Corresponding author at: Department of Emergency Medicine, Linkou Chang Gung Memorial Hospital and Keelung Chang Gung Memorial Hospital, Taiwan.

E-mail addresses: [email protected], [email protected] (C.-Y. Chien).

1 Postal address: Department of Emergency Medicine, Chang Gung Memorial Hospital, 5 Fuxing Street, Guishan District, Taoyuan 333, Taiwan.

rhythm by an Automated external defibrillator [2]. Coronary ar- tery disease is considered to be responsible for the majority of OHCA cases [3-5].

In the 2015 American Heart Association Guidelines for Cardiopulmo- nary Resuscitation (CPR) and Emergency Cardiovascular Care, it is recom- mended to perform emergency coronary angiography in resuscitated patients after cardiac arrest with or without ST-segment elevation [6]. As immediate percutaneous coronary intervention (PCI) after the occurrence of OHCA is associated with reduced mortality and adverse events [7,8], it is logical that emergency PCI plays an important role in determining Survival and neurological outcomes. Nevertheless, the immediate availability of PCI, namely, hospitals with the capability to perform PCI immediately, remains a contentious issue. To date, few studies have focused on whether the characteristics of hospitals to which OHCA patients are directly transported are associated with survival and neurological outcomes.

http://dx.doi.org/10.1016/j.ajem.2017.03.032

0735-6757/(C) 2017

Therefore, in the present study, we aimed to identify hospital char- acteristics and parameters of emergency medical service, including scene time interval (STI) and direct ambulance delivery to intensive heart hospitals (defined as hospitals with 24/7 PCI availability and consultable cardiologists), that could serve as predictors of survival or outcome in Taoyuan, Taiwan.

The OHCA database in Taoyuan City, a regional prospective registry database of OHCA, was used in the present study. A total of 546 consecu- tive EMS-assessed OHCA patients with shockable rhythms were delivered to 13 hospitals (including 8 intensive heart hospitals and 5 non-intensive heart hospitals) located in Taoyuan. The data were collected and analysed to determine the significance of each parameter in the Chain of survival.

Methods

Study design and setting

This was a retrospective observational study. The data used were from the OHCA database, a prospectively collected database to which reporting is mandatory by all emergency departments within Taoyuan City, Taiwan. The OHCA database includes all of Taoyuan City (population 2,132,854; area, 1221 km2) and contains 35 EMSs including one medical centre. The primary endpoint was survival to discharge, and the secondary end- point was good Cerebral Performance Category [9].

emergency medical technicians provide primary prehospital emergency care in Taoyuan. In 2010, 104 EMT-1 (EMT-basic), 666 EMT-

2 (EMT intermediate), and 36 EMT-P (EMT-P) personnel were employed by Taoyuan’s EMS stations. By Taiwanese law, EMTs cannot perform thoracotomy or pericardiocentesis in the field, and only certi- fied EMT-Ps are allowed to perform endotracheal tube intubation and administer epinephrine intravenously. The laryngeal mask airway (LMA) technique and placement of intravenous lines for delivering fluids can be performed by EMT-2s and EMT-Ps, while all grades of EMTs can operate AEDs.

Data collection was based on the Utstein template and data were collected from the EMS running sheet and by review of hospital medical records. Information obtained included age, gender, location of arrest, initial rhythm, hospital, EMS parameters, provision of CPR by a bystand- er, presence of a witness at collapse, level of life support provided, and neurological outcome.

Intensive heart hospitals were defined as hospitals with immediate 24/7 PCI availability and consultable cardiologists. Although staff at non-intensive heart hospitals are capable of performing PCI, it is not promptly available and cardiologists are not immediately consultable. Therefore, patients who need consulting cardiologists or immediate PCI must be transferred to the nearest intensive heart hospital.

Selection of participants

A total of 546 patients with shockable rhythms treated in the emergency departments of hospitals located in Taoyuan, Taiwan, from January 2012 to December 2015 were included in this study. Only non-traumatic patients who were >= 18 years of age, had a body temper- ature N 30?C, and had at least one AED shock were included in this study (Fig. 1). As all enrolled patients experienced at least one AED shock, the electrocardiograms (ECG and EKG) stored in the AED units were printed out and examined by an EMT-P. The records of Initial shockable rhythm were then confirmed and documented.

Outcome measures

The primary outcome was survival after 24 h. The secondary out- comes were survival to discharge and a CPC grade of 1-2. The CPC scale was used to assess neurological outcome. A CPC score of 1 denotes good cerebral performance (mild or no neurological disability); 2, moderate cerebral disability (conscious and able to function

Fig. 1. Patient enrolment flowchart.

independently); 3, severe cerebral disability (conscious, but dependent on others for daily support); 4, coma or vegetative state; and 5, death. Demographic variables and other parameters were compared among the various outcome groups.

Definition of EMS parameters

The response time was defined as the interval from calling 119 to the arrival of an ambulance. The definition of STI was the time EMS remained at the scene. The transport time was estimated as the time taken by an ambulance from leaving the scene to arrival at a hospital. The EMS time was the sum of response time, STI, and transport time, that is, time from calling 119 to the arrival of an EMS vehicle at a hospital.

Statistical analysis

Statistical analyses were performed using the IBM SPSS software (ver. 20; IBM Corp., Armonk, NY, USA) unless otherwise stated. A P-value of b 0.05 was considered to indicate statistical significance. Categorical data are reported as percentages, and continuous variables with normal distributions as means +- standard deviations (SDs). The chi-squared test was applied for between-group comparisons of demo- graphic categorical variables, and Student’s t-test was used to compare continuous variables when normality assumptions were met. Odds ratios and 95% confidence intervals (CIs) were calculated via both uni- variate and multivariate analyses. Factors significantly associated with the outcomes were included in a multivariate analysis. In addition, to vi- sualise the relationship between poor CPC and STI, a quadratic spline univariate logistic regression model was carried out using R (a free language and environment for statistical computing) to estimate odds ratios with 95% CIs of poor neurological outcome as a function of STI.

Ethics statement

This study was reviewed and approved by the Institutional Review Board of Linkou Chang Gung Memorial Hospital (Taiwan, ROC; IRB Per- mit No.: 201600635B0).

Results

Among 9455 OHCA cases, patients who did not meet the inclusion criteria (i.e. 8909 patients whose family refused to go to hospital [N

= 2107; 22.3%], with low body temperature [N = 112; 1.2%], with

trauma [N = 1160; 12.3%], younger than 18 years of age [N = 107; 1.1%], with missing data [N = 74; 0.8%], with Non-shockable rhythm [N = 5274; 55.8%], or with return of spontaneous circulation [ROSC] be- fore arrival at hospital [N = 75; 0.8%]) were excluded. Therefore, a total of 546 patients from 2012 to 2015 were enrolled in this study (Fig. 1).

Overall, patients were predominantly male (78%), with an average age of 62.4 years (SD 15.6 years). Cardiac arrest was witnessed in 68.1% of the cases and occurred mostly at the patient’s residence (63.7%). Among the 372 witnessed collapses, 36 cases were witnessed by EMTs. Bystander CPR was performed in 40.1% (219/546) of the pa- tients. The mean response time, STI, transport time, and EMS time were 7.5, 12.0, 6.2, and 26.0 min, respectively. Of the cases, 56.6% and 43.4% received basic and advanced life support (BLS/ALS), respectively (Table 1).

OHCA patients were delivered to 13 hospitals, comprising 8 inten- sive and 5 non-intensive heart hospitals. Among the 546 OHCA cases, 474 (86.8%) were delivered to the intensive heart hospitals, at which PCI and cardiologists are available 24/7 (Table 1).

To identify the key parameters influencing the outcomes, OHCA shockable cases were analysed according to whether they survived for 24 h, were discharged alive, or recovered with good CPC. Among 546 pa- tients analysed, 139 (25.5%) patients survived the first 24 h, 64 (11.7%) survived to discharge, and 33 (6.0%) recovered with good neurological outcomes (CPC 1-2).

As shown in Table 2, survival after 24 h differed significantly accord- ing to age, gender, location of arrest, treatment at intensive heart hospi- tals, response time, and whether collapse was witnessed. Age, location of arrest, treatment at intensive heart hospitals, response time, STI, EMS time, and witnessed collapse differed between patients who did and did not survive to discharge. Moreover, neurological outcome dif- fered significantly according to age, gender, place of arrest, response time, STI, EMS time, and witnessed collapse. Of note, there were no sta- tistical significance in time spent on transport, provision of bystander CPR, and type of life support provided.

The results of univariate and multivariate analyses are shown in Table 3. In multivariate analysis, younger patients were significantly more likely to survive after 24 h and to discharge and to have good

Table 1

Characteristics of the study population.

Total

Number 546

Age, y 62.42 (15.619)

Gender

Male 426 (78.00%)

Female 120 (22.00%)

Location of arrest

Public 198 (36.3%)

Residential 348 (63.7%)

Intensive heart hospital

Yes 474 (86.8%)

No 72 (13.2%)

EMS parameter, min

Response time 7.51 (3.062)

Scene time interval 12.05 (4.739)

Transport time 6.21 (4.422)

EMS time 25.95 (7.628)

Provision of bystander CPR

Yes 219 (40.1%)

No 327 (59.9%)

Witnessed collapse

Yes 372 (68.1%)

No 174 (31.9%)

Type of life support

BLS 309 (56.60%)

ALS 237 (43.40%)

Values are expressed as number (%) or mean (SD) as appropriate. EMS, emergency medical system; CPR, cardiopulmonary resuscitation; BLS, basic life support; ALS, advanced life support.

neurological outcomes. A longer response time was associated with lower probabilities of survival to 24 h and to discharge, and a worse CPC score. Patients who were delivered to intensive heart hospitals had a higher likelihood of surviving to discharge (OR: 4.32; 95% CI: 1.27-14.70), but not a better CPC score. If a collapse was witnessed, pa- tients were more likely to survive to discharge (OR: 2.23; 95% CI: 1.11- 4.48) and have a better CPC score (OR: 3.52; 95% CI: 1.03-11.98). In ad- dition, longer STI was associated with a lower likelihood of survival to discharge (OR: 0.86; 95% CI: 0.76-0.97) and good cerebral performance (OR: 0.89; 95% CI: 0.81-0.99). Fig. 2 shows the relationship between STI and poor CPC in OHCA patients with shockable rhythms. As a predictor of recovery with poor CPC, the odds ratio increased with increasing STI. The spline curve clearly indicates a marked association between STI and poor neurological outcome, suggesting a statistically stable estimate.

Discussion

The overall survival of OHCA patients is differentially affected by the components of the chain of survival. The objective of the present study was to identify the key parameters that influence the outcomes of OHCA shockable patients, especially those involved in the fourth and fifth ele- ments of the chain of survival, including direct Ambulance transport to intensive heart hospitals, response time, and STI.

Previously, Patel et al. reported that patients who had undergone coronary angiography or PCI were more likely to survive to discharge [10]. In addition, immediate PCI is associated with improved survival in patients with or without ST-segment elevation [3], not only in terms of short-term survival but also long-term prognosis [7,11]. Early access (within 6 h of arrival at the Emergency Department) to the cardi- ac catheterisation laboratory for patients with shockable rhythm is asso- ciated with better survival and neurological outcomes [12]. These studies demonstrated that patients receiving PCI have a higher chance of survival. In the present study, a multivariate analysis revealed that OHCA shockable patients transported to intensive heart hospitals had a higher likelihood of surviving to discharge. Of note, the data were col- lected in a prospective registry setting, and no PCI performance was re- corded at that time point. Therefore, our results indicate that direct ambulance delivery to intensive heart hospitals, which support imme- diate PCI and have a consultable cardiologist, is crucial for the survival of OHCA shockable patients, irrespective of subsequent PCI perfor- mance. This suggests that, from the point of ambulance dispatch, OHCA shockable patients should be transported directly to an intensive heart hospital for enhanced post-resuscitation care and to avoid unnec- essary hospital transfer.

Hunter et al. analysed whether primary EMS transport to hospitals with certain characteristics showed any association with improved sur- vival in OHCA patients [13]. The characteristics analysed included 24/7 PCI availability, trauma centre status, and large (N 24-bed) ICU. No sig- nificant independent association between these characteristics and sur- vival to discharge was found. Notably, in their system, EMS personnel are instructed to perform resuscitative measures for 30 min or until ROSC is achieved at the scene. Patients with ROSC are then transported to an area hospital. In contrast, patients with ROSC before arrival at hos- pital were excluded from our study, which results in a baseline differ- ence between their and our studies. Others have reported that the characteristics of hospitals are not associated with survival [14,15] or neurological recovery [15,16]. All three of these studies included cases of both shockable and non-shockable rhythms. Patients transported to cardiac centres showed a statistically significant survival advantage, with odds ratios of 1.40 (95% CI: 1.12-1.74) [14] and 2.39 (95% CI: 1.33-4.28) [15]. Mumma et al. stratified ST-elevation myocardial infarc- tion (STEMI) centres (defined as hospitals with 24/7 PCI capability) into those with >= 40 and b 40 OHCA cases per year and found that patients treated at a STEMI centre had a higher likelihood of recovering with good neurological performance (OR 1.32 [95% CI 1.06-1.64] and 1.63 [95% CI 1.35-1.97], respectively), irrespective of the annual OHCA

Table 2

Demographic characteristics of the study population.

Alive over 24 h

Alive to discharge

Good CPC

No

(N = 407)

Yes

(N = 139)

P value

No

(N = 482)

Yes

(N = 64)

P value

No

(N = 513)

Yes

(N = 33)

P value

Age, y

63.34 (15.667)

59.71 (15.212)

0.018?

63.24 (15.550)

56.20 (14.829)

0.001?

62.90 (15.522)

54.82 (15.384)

0.004?

Gender Male

309 (75.92%)

117 (84.17%)

0.043?

370 (76.76%)

56 (87.50%)

0.051

394 (76.80%)

32 (96.97%)

0.004?

Female

98 (24.08%)

22 (15.83%)

112 (23.24%)

8 (12.50%)

119 (23.20%)

1 (3.03%)

Location of arrest Public

136 (33.42%)

62 (44.60%)

0.018?

167 (34.65%)

31 (48.44%)

0.031?

175 (34.11%)

23 (69.70%)

0.000?

Residential

271 (66.58%)

77 (55.40%)

315 (65.35%)

33 (51.56%)

338 (65.89%)

10 (30.30%)

Intensive heart hospital Yes

344 (84.52%)

130 (93.53%)

0.007?

413 (85.68%)

61 (95.31%)

0.030?

443 (86.35%)

31 (93.94%)

0.292

No

63 (15.48%)

9 (6.47%)

69 (14.32%)

3 (4.69%)

70 (13.65%)

2 (6.06%)

EMS parameter, min Response time

7.70 (3.226)

6.99 (2.455)

0.018?

7.63 (3.123)

6.63 (2.394)

0.013?

7.59 (3.098)

6.33 (2.146)

0.022?

Scene time interval

12.23 (4.829)

11.53 (4.442)

0.132

12.21 (4.807)

10.81 (4.015)

0.026?

12.20 (4.773)

9.64 (3.408)

0.002?

Transport time

6.38 (4.560)

5.69 (3.961)

0.111

6.32 (4.498)

5.38 (3.731)

0.109

6.26 (4.438)

5.45 (4.154)

0.314

EMS time

26.48 (7.978)

24.37 (6.527)

0.005?

26.35 (7.686)

22.92 (6.462)

0.001?

26.23 (7.677)

21.55 (5.167)

0.000?

Provision of bystander CPR

160 (39.31%)

59 (42.45%)

0.515

189 (39.21%)

30 (46.88%)

0.240

202 (39.38%)

17 (51.52%)

0.168

Witnessed collapse

268 (65.85%)

104 (74.82%)

0.050?

319 (66.18%)

53 (82.81%)

0.007?

342 (66.67%)

30 (90.91%)

0.003?

Type of life support

BLS

236 (57.99%)

73 (52.52%)

0.262

271 (56.22%)

38 (59.38%)

0.633

287 (55.95%)

22 (66.67%)

0.228

ALS

171 (42.01%)

66 (47.48%)

211 (43.78%)

26 (40.63%)

226 (44.05%)

11 (33.33%)

Values are expressed as number (%) or mean (SD) as appropriate. CPC, cerebral performance category; EMS, emergency medical system; CPR, cardiopulmonary resuscitation; BLS, basic life support; ALS, advanced life support.

* P-value b 0.05.

volume of the centre [16]. In contrast, only patients with shockable rhythms were enrolled in our study. Both survival (after 24 h and at dis- charge) and neurological recovery were investigated. Although Wnent et al. examined the same outcomes, they found that PCI centres are in- dependently associated with good neurological outcomes; no such sig- nificance was detected in our study. This inconsistency is likely due to differences in the study design and geographical location.

In the multivariate analysis, age was independently associated with all three outcomes. As age increases, the likelihood of survival and re- covery with good neurological outcomes decreases. Although the values are close to one, the odds ratios are similar to those reported previously; older age reduces the likelihood of survival to discharge [10] and in- creases the probability of a poor neurological outcome [17]. As age

significantly impacts survival and neurological outcomes (Tables 2 and 3), the female patients’ relatively lower survival rate (8/120 female pa- tients versus 56/426 male patients who survived to discharge) may at- tribute to their higher average age (68.83 years) as compared with the male patients (60.61 years). In addition, among the 426 male patients,

176 (41.3%) patients experienced OHCA at public locations, 310

(72.8%) patients were witnessed, and 174 (40.8%) patients received bystander CPR. On the contrary, the proportions were lower in female patients [22 (18.3%), 61 (51.7%), and 45 (37.5%) patients, respectively]. In the multivariate analysis (Table 3), the gender showed no favourable effect on three outcomes analysed. Thus, consistent with Safdar and col- leagues’ finding, it seems that there was no independent effect of gender on OHCA outcomes [18].

Table 3

Odds ratios of all groups.

Univariate analysis

Multivariate analysis

Factors

Odds ratio

95% CI

Odds ratio

95% CI

Alive over 24 h

Age

0.985

0.973-0.997(P = 0.018)

0.986

0.973-0.999(P = 0.047?)

Male

1.687

1.014-2.806(P = 0.044)

1.420

0.834-2.416(P = 0.197)

Public

1.604

1.083-2.376(P = 0.018)

1.396

0.919-2.119(P = 0.117)

Intensive heart hospital

2.645

1.279-5.473(P = 0.009)

2.884

1.373-6.059(P = 0.05)

Witnessed collapse

1.541

0.998-2.349(P = 0.051)

Response time

0.915

0.850-0.985(P = 0.019)

0.921

0.852-0.995(P = 0.037?)

Alive to discharge

Age

0.971

0.955-0.988(P = 0.001)

0.967

0.948-0.985(P = 0.000?)

Male

2.119

0.981-4.578(P = 0.056)

Public

1.772

1.048-2.995(P = 0.033)

1.082

0.603-1.940(P = 0.792)

Intensive heart hospital

3.397

1.037-11.131(P = 0.043)

4.317

1.267-14.702(P = 0.019?)

Witnessed collapse

2.462

1.252-4.841(P = 0.009)

2.233

1.113-4.481(P = 0.024?)

Response time

0.866

0.774-0.968(P = 0.011)

0.932

0.872-0.996(P = 0.012?)

Scene time interval

0.931

0.875-0.992(P = 0.027)

0.857

0.759-0.967(P = 0.037?)

Good CPC

Age

0.967

0.945-0.990(P = 0.004)

0.975

0.950-0.999(P = 0.046?)

Male

9.665

1.307-71.478(P = 0.026)

5.108

0.667-39.111(P = 0.116)

Public

4.442

2.068-9.542(P = 0.000)

2.198

0.961-5.024(P = 0.062)

Intensive heart hospital

Witnessed collapse

2.449

5.000

0.573-10.462(P = 0.227)

1.505-16.616(P = 0.009)

3.517

1.033-11.978(P = 0.044?)

Response time

0.822

0.701-0.964(P = 0.016)

0.829

0.702-0.981(P = 0.029?)

Scene time interval

0.860

0.779-0.948(P = 0.002)

0.893

0.808-0.986(P = 0.025?)

* P-value b 0.05; CPC, cerebral performance category.

Fig. 2. The odds ratios of poor CPC from a restricted cubic spline model. Estimated odds ratios (solid line) with 95% confidence intervals (dashed lines) of poor neurological outcome as a function of the STI are shown. The odds ratio of poor CPC increases with increasing STI.

The value of witnessed collapse was addressed in a study conducted in Sweden, in which the likelihood of survival increased twofold if the collapse was witnessed [19]. Moreover, the survival rate of OHCA pa- tients was higher if the collapse was witnessed, by either a member of the EMS or a bystander [20]. In the present study, witnessed collapse was an independent predictor of both survival to discharge and good CPC (odds ratios of 2.23 and 3.52, respectively), which is consistent with previous findings.

A shorter Ambulance response time suggests early recognition and

access to treatment by EMTs, indicating an increased likelihood of sub- sequent survival. O’Keeffe et al. reported that, along with initial rhythm (with ventricular fibrillation) and witnessed arrest, ambulance re- sponse time is a critical determinant of survival to discharge in OHCA patients [21]. Their results showed that a 1 min reduction in response time could improve the likelihood of survival by 24%. In addition, provi- sion of bystander CPR prolonged the response Time threshold by q = 1 min [22]. The significance of STI, on the other hand, was addressed in previous studies using a cut-off value of 14 [23] or 8-16 min [24]. The difference in STI cut-off values may be attributable in part to the variations in protocols and policies among EMS systems and to local geographic restrictions. The density and distribution of hospitals and EMS stations have a marked influence on STI values. Overall, a prolonged STI is correlated with poor neurological recovery after the oc- currence of OHCA (Fig. 2).

The unselected prospective registry system used in the present study provides a relatively unselected cohort for data analysis, which may serve as a more close-to-reality estimate of OHCA outcomes in rou- tine practice. Our results showed that direct ambulance transport to in- tensive heart hospitals provides a better survival strategy for OHCA patients with shockable rhythms. This may not only help EMS providers decide which hospital OHCA shockable patients should be delivered to, but could also serve as a recommendation. Integration of this strategy into a local EMS protocol in the near future may face various obstacles. Nevertheless, effort should focus on facilitating the establishment of a feasible system to reduce response time and efficiently deliver patients with shockable rhythms to intensive heart hospitals after the occur- rence of cardiac arrest.

In addition to parameters evaluated in the present study, some un- measured and immeasurable confounding factors assessed by medical dispatcher could provide valuable information regarding patients’ sur- vival. Previous studies have found that the presence of gasping (agonal respiration) is associated with increased survival [25,26]. As gasping decreases rapidly with time, a prompt recognition of gasping and following resuscitation provided by Emergency Medical Dispatcher or

bystander is imperative [27]. Nevertheless, gasping is frequently overlooked in current EMS systems. For patients’ benefit, the influence of gasping should be considered in future studies evaluating survival by resuscitation in OHCA patients (both in-hospital and out-of-hospital). The validated findings should subsequently be incorporated into the emergency medical training programmes and clinical practice.

This study was limited by its retrospective nature. Statistical bias may have been introduced by the small sample size, limited local popu- lation, and selection bias. The lack of information regarding the details of CPR performance, for example, dispatcher-assisted CPR, recorded in the OHCA database limited its generalisation. In addition, no data were included in terms of whether therapeutic hypothermia, PCI, or extracor- poreal membrane oxygenation (ECMO) was performed; these tech- niques greatly impact both survival and neurological outcomes. In 2013, a new policy regarding AED distribution and the Good Samaritan Law were implemented in Taiwan, which may have influenced the re- sults from that time onwards. Nevertheless, our findings provide valu- able information on the various parameters involved in the chain of survival. The factors mentioned above should be included in future studies to enable precise and generalisable prediction of the outcomes of OHCA shockable patients, which could be used in clinical practice.

Conclusion

Direct ambulance delivery to intensive heart hospitals was associat- ed with a higher Probability of survival to discharge in OHCA shockable patients. A witnessed collapse was correlated with discharge alive and good cerebral performance. Survival and neurological outcomes became poorer as response time and STI increased.

Conflicts of interest

The author has no conflict of interest to declare.

Funding

This research did not receive any specific grant from funding agen- cies in the public, commercial, or not-for-profit sectors.

Prior presentations

None.

Funding sources/disclosures

None.

Conflicts of interest

None.

References

  1. Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, et al. Heart dis- ease and stroke statistics-2016 update: a report from the American Heart Associa- tion. Circulation 2016;133(4):e38-360.
  2. Nichol G, Thomas E, Callaway CW, Hedges J, Powell JL, Aufderheide TP, et al. Regional variation in out-of-hospital cardiac arrest incidence and outcome. JAMA 2008; 300(12):1423-31.
  3. Dumas F, Cariou A, Manzo-Silberman S, Grimaldi D, Vivien B, Rosencher J, et al. Im- mediate percutaneous coronary intervention is associated with better survival after out-of-hospital cardiac arrest: insights from the PROCAT (Parisian Region Out of hospital Cardiac ArresT) registry. Circ Cardiovasc Interv 2010;3(3):200-7.
  4. Kern KB, Lotun K, Patel N, Mooney MR, Hollenbeck RD, McPherson JA, et al. Out- comes of comatose cardiac arrest survivors with and without ST-segment elevation myocardial infarction: importance of coronary angiography. JACC Cardiovasc Interv 2015;8(8):1031-40.
  5. Vyas A, Chan PS, Cram P, Nallamothu BK, McNally B, Girotra S. Early coronary angi- ography and survival after out-of-hospital cardiac arrest. Circ Cardiovasc Interv 2015;8(10).
  6. Callaway CW, Donnino MW, Fink EL, Geocadin RG, Golan E, Kern KB, et al. Part 8: post-cardiac arrest care: 2015 American Heart Association guidelines update for car- diopulmonary resuscitation and emergency cardiovascular care. Circulation 2015; 132(18 Suppl 2):S465-82.
  7. Geri G, Dumas F, Bougouin W, Varenne O, Daviaud F, Pene F, et al. Immediate percu- taneous coronary intervention is associated with improved short- and long-term survival after out-of-hospital cardiac arrest. Circ Cardiovasc Interv 2015;8(10).
  8. Liu HW, Pan W, Wang LF, Sun YM, Li ZQ, Wang ZH. Impact of emergency percutane- ous coronary intervention on outcomes of ST-segment elevation myocardial infarc- tion patients complicated by out-of-hospital cardiac arrest. Chin Med J (Engl) 2012; 125(8):1405-9.
  9. Edgren E, Hedstrand U, Kelsey S, Sutton-Tyrrell K, Safar P. Assessment of neurologi- cal prognosis in comatose survivors of cardiac arrest. BRCT I Study Group. Lancet (London, England) 1994;343(8905):1055-9.
  10. Patel N, Patel NJ, Macon CJ, Thakkar B, Desai M, Rengifo-Moreno P, et al. Trends and outcomes of coronary angiography and percutaneous coronary intervention after out-of-hospital cardiac arrest associated with ventricular fibrillation or pulseless ventricular tachycardia. JAMA Cardiol 2016;1(8):890-9.
  11. Dumas F, White L, Stubbs BA, Cariou A, Rea TD. Long-term prognosis following re- suscitation from out of hospital cardiac arrest: role of percutaneous coronary inter- vention and therapeutic hypothermia. J Am Coll Cardiol 2012;60(1):21-7.
  12. Garcia S, Drexel T, Bekwelem W, Raveendran G, Caldwell E, Hodgson L, et al. Early access to the cardiac catheterization laboratory for patients resuscitated from cardi- ac arrest due to a shockable rhythm: the Minnesota Resuscitation Consortium Twin Cities Unified Protocol. J Am Heart Assoc 2016;5(1).
  13. Hunter BR, O’Donnell DP, Kline JA. Receiving hospital characteristics associated with

    survival in patients transported by emergency medical services after out-of-hospital cardiac arrest. Acad Emerg Med 2016;23(8):905-9.

    Stub D, Smith K, Bray JE, Bernard S, Duffy SJ, Kaye DM. Hospital characteristics are associated with patient outcomes following out-of-hospital cardiac arrest. Heart (British Cardiac Society) 2011;97(18):1489-94.

  14. Wnent J, Seewald S, Heringlake M, Lemke H, Brauer K, Lefering R, et al. Choice of hospital after out-of-hospital cardiac arrest-a decision with far-reaching conse- quences: a study in a large German city. Crit Care 2012;16(5):R164.
  15. Mumma BE, Diercks DB, Wilson MD, Holmes JF. Association between treatment at an ST-segment elevation myocardial infarction center and neurologic recovery after out-of-hospital cardiac arrest. Am Heart J 2015;170(3):516-23.
  16. Maupain C, Bougouin W, Lamhaut L, Deye N, Diehl JL, Geri G, et al. The CAHP (Car- diac Arrest Hospital Prognosis) score: a tool for risk stratification after out-of-hospi- tal cardiac arrest. Eur Heart J 2015.
  17. Safdar B, Stolz U, Stiell IG, Cone DC, Bobrow BJ, deBoehr M, et al. Differential survival for men and women from out-of-hospital cardiac arrest varies by age: results from the OPALS study. Acad Emerg Med 2014;21(12):1503-11.
  18. Herlitz J, Engdahl J, Svensson L, Angquist KA, Young M, Holmberg S. Factors associ- ated with an increased chance of survival among patients suffering from an out- of-hospital cardiac arrest in a national perspective in Sweden. Am Heart J 2005; 149(1):61-6.
  19. Sasson C, Rogers MA, Dahl J, Kellermann AL. Predictors of survival from out-of-hos- pital cardiac arrest: a systematic review and meta-analysis. Circ Cardiovasc Qual Outcomes 2010;3(1):63-81.
  20. O’Keeffe C, Nicholl J, Turner J, Goodacre S. Role of ambulance response times in the survival of patients with out-of-hospital cardiac arrest. Emerg Med J 2011;28(8): 703-6.
  21. Ono Y, Hayakawa M, Iijima H, Maekawa K, Kodate A, Sadamoto Y, et al. The response time threshold for predicting favourable neurological outcomes in patients with by- stander-witnessed out-of-hospital cardiac arrest. Resuscitation 2016;107:65-70.
  22. Kim TH, Shin SD, Kim YJ, Kim CH, Kim JE. The scene time interval and basic life sup- port termination of resuscitation rule in adult out-of-hospital cardiac arrest. J Korean Med Sci 2015;30(1):104-9.
  23. Shin SD, Kitamura T, Hwang SS, Kajino K, Song KJ, Ro YS, et al. Association between resuscitation time interval at the scene and neurological outcome after out-of-hospi- tal cardiac arrest in two Asian cities. Resuscitation 2014;85(2):203-10.
  24. Clark JJ, Larsen MP, Culley LL, Graves JR, Eisenberg MS. Incidence of agonal respira- tions in sudden cardiac arrest. Ann Emerg Med 1992;21(12):1464-7.
  25. Martens P, Mullie A, Vanhaute O. Clinical status before and during cardiopulmonary resuscitation versus outcome in two consecutive databases. Belgian CPCR Study Group. Eur J Emerg Med 1995;2(1):17-23.
  26. Bobrow BJ, Zuercher M, Ewy GA, Clark L, Chikani V, Donahue D, et al. Gasping during cardiac arrest in humans is frequent and associated with improved survival. Circula- tion 2008;118(24):2550-4.

Leave a Reply

Your email address will not be published. Required fields are marked *